<!DOCTYPE html>
<html>
	<head>
		<meta charset="UTF-8">
		<title></title>
		<script>
			//js是弱类型的语言
			var w=15;
			alert(w);
			w="元坤说：哥的牛逼，不要编译";
			alert(w);
			
			
		</script>
	</head>
	<body>
	</body>
</html>
